CH620904A5 - Process for the preparation of 1-aminobenzene-4- and -5-beta-sulphatoethyl-sulphone-2-sulphonic acid and of the corresponding oxyethylsulphone and vinylsulphone compounds - Google Patents

Description

The present invention relates to the preparation of compounds of the formulas Ia and / or Ib

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(la)

65

(la)

620904

NH

where X is a grouping

-CHJJ-CHo-OSOJH (2) -CH2-CH2-OH (3) or -CH = CH2 (4)

which is characterized in that compounds of the formula 5

NH

HO

3rd

S0o-X

wherein X has the meaning given above, are treated in aqueous mineral acids with acid concentrations of 1 to 99% by weight, preferably 30 to 96% by weight, at temperatures from 80 to 140 ° C., preferably 100 to 130 ° C.

Mineral acids include hydrochloric acid, phosphoric acid and preferably sulfuric acid. For the reversible splitting off of a sulfonic acid group, the compound of formula 5 is dissolved in water, the solution is mixed with mineral acid, for example hydrochloric acid, phosphoric acid or sulfuric acid, and heated to 80 to 140 ° C. under normal pressure or under pressure, with an increase in the acid concentrations at the same time Water can be distilled off.

Appropriately, however, the procedure is such that the sulfonation batches in which a starting product of the formula 6

NH

where X is the radicals of the above formulas 2 and 4, in mixtures of sulfuric acid and sulfur trioxide or sulfuric acid and chlorosulfonic acid, the molar ratio between the starting product of formula 6 and sulfur trioxide or chlorosulfonic acid 1: 2.2 to 1: 3 can be converted at temperatures between 90 and 150 ° C., preferably 100 to 130 ° C., into either pure compounds of the formula 5 or mixtures of compounds of the formula 5 and in quantitative subordinate proportions between 1 and 10% of compounds of the formula 1, with water or mineral acids diluted with water up to water contents between 30 and 99%, preferably 80 to 95%, and heated until the quantitative cleavage to give pure compounds of formulas 1 to 80 to 140 ° C, preferably 100 to 130 ° C.

The compounds of the formula 1 are generally isolated from the mineral acid solutions after neutralization with alkali metal or alkaline earth metal hydroxides or carbonates by salting out with alkali metal halides or by spray drying. When using larger acid surpluses, such as sulfuric acid, which is introduced as described above from the sulfonation process of the preliminary stage, about 85% is expediently neutralized with calcium oxide or carbonate and finally with about 15% soda, separated from above 65 ° C precipitated calcium sulfate hemihydrate and wins the desired compound of formula 1 by spray drying or salting out with sodium or potassium chloride. When using mineral acids with a water content greater than 30% by weight, predominantly compounds of the formula 1 in which X denotes the group -CH2-CH2-OH (3) are obtained, which after isolation and drying by esterification with 95-100% iger sulfuric acid at 0 to 40 ° C, preferably 20 to 30 ° C, in the compounds of formula 1, wherein X is -CH2-CH2-OSOaH (2), can be converted. Compounds of the formula 1 in which X denotes the radical -CH = CH2 (4) can also be obtained from compounds of the formula 1 in which X corresponds to the formula -CH2-CH2--0S03H (2) by treatment with aqueous alkalis at 20 -100 ° C, preferably at 40-70 ° C can be obtained.

The process of converting compounds of Formula 5 to compounds of Formula 1 is new and unpredictable. The reaction proceeds quantitatively and results in high-purity end products, so that the compounds of formula 1 known per se are obtained in higher purity and according to technically feasible processes in higher yields than in the prior art.

For example, the l-aminobenzene-4-β-sulfato-ethylsulfone-2-sulfonic acid is obtained in a yield of 70-80% of theory using a method described in DOS 2 154 943. Th. Obtained by sulfonation of l-aminobenzene-4-ß-sulfatoäthyIsuIfon with almost stoichiometric amounts of S03, the remaining 20-30% being a significant proportion of unsulfated starting product. According to the new method according to the invention, the desired compound is obtained in a yield of 95-98% of theory after over-sulfonation with an excess of SO 3 and subsequent cleavage. Th. In pure form.

The 1-aminobenzene-5-ß-sulfatoethylsulfone-2- that is formed during the desulfonation of l-aminobenzene-5-ß-sulfa-ethylsulfone-2,4-disulfonic acid, which is accessible to DOS 2 352 059 by the sulfonation process. After alkali treatment for conversion to the corresponding vinylsulfone compound, sulfonic acid was found to be structurally identical to the compound obtained from l-chloro-2-nitrobenzene-4-sulfochloride by reduction to sulfinic acid and reaction with ethylene oxide to l-chloro-2-nitrobenzene -4-ß-hydroxyethylsulfone, chlorine substitution with alkali sulfite to 1-nitrobenzene-5-ß-oxyethylsulfone-2-sulfonic acid, reduction to the corresponding amino compound, esterification with 100% sulfuric acid to l-amino-5-ß- sulfatäthylsulfon-2-sul-fonic acid and conversion to the vinyl form by alkali treatment. Technically, this process can only be carried out with extensive protective measures, since l-chloro-2-nitrobenzene-4-sulfochloride and l-chloro-2-nitro-benzene-4-ß-hydroxyethylsulfone show skin-damaging and allergy-causing effects. In contrast, according to

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The method according to the invention enables simple and safe production of the desired connection.

The compounds of formula 1 mentioned are important starting materials for dyes, as are described in German Offenlegungsschriften 2,154,942, 2,161,760 and 2,222,032.

The following examples serve to illustrate the invention. The parts specified are parts by weight.

example 1

343 parts of l-amino-5-vinylsulfone-2,4-disu] fonic acid are dissolved in 2000 parts of water. After dropwise addition of 250 parts of 100% sulfuric acid, the temperature of the mixture being kept at 20 ° C. by external cooling, the mixture is heated to 110-120 ° C. for 4 hours and 1000 parts of water are distilled off. After cooling to room temperature, the precipitated l-aminobenzene-5-vinylsulfone-2-sulfonic acid is suctioned off. The yield is 95% of theory.

Example 2

343 parts of l-aminobenzene-5-vinylsulfone-2,4-disulfonic acid are stirred in 3000 parts of 31% hydrochloric acid. After refluxing for 2 hours, the l-aminobenzene-5-vinylsulfonic acid is obtained in 99% of theory after cooling to room temperature. Th.

Example 3

343 parts of l-aminobenzene-5-vinylsulfone-2,4-disulfonic acid are stirred in 800 parts of water, mixed with 250 parts of orthophosphoric acid and heated under reflux for 4 hours. The quantitative yield is 1-amino-benzene-5-vinylsulfone-2-sulfonic acid, which can be processed directly without intermediate cleaning, for example by diazotization and dye coupling.

Example 4

50 parts of 1-aminobenzene-5-β-sulfatoethylsulfone-2,4-disulphonic acid are heated in 150 parts of 60% strength sulfuric acid at 100 ° C. for 4 hours. The β-sulfatoethylsulfone group is then saponified to give the β-oxyethylsulfone group and the sulfonic acid group is split off in the 4-position. The yield of l-aminobenzene-5-β-oxyethylsulfone-2-sulfonic acid is quantitative.

Example 5

281 parts of l-aminobenzene-3-ß-sulfatoethylsulfone are introduced into 843 parts of 100% strength sulfuric acid at 15-20 ° C. with cooling and stirring and with the addition of atmospheric moisture. After 1 hour, 350 parts of oleum with a SOE content of 65% by weight are slowly added dropwise, the temperature being kept at 15-20 ° C. by external cooling. The mixture is then heated to l-aminobenzene-5-β-sulfatoethyl-sulfone-2,4-disulfonic acid for 12 hours at 130 ° C. until the sulfonation has ended, then 265 parts of 50% strength aqueous sulfuric acid are slowly added at the same temperature and the mixture is heated another 12 hours at 130 ° C. The mixture is then stirred into ice after cooling to 25 ° C. 780 parts of calcium oxide are added, then with calcium. Soda is adjusted to pH 6.0 and then heated to 70 ° C. After filtering off the calcium sulfate hemihydrate, the l-aminobenzene-5-β-sulfatoethylsulfone-2-sulfonic acid as the sodium salt is evaporated to dryness with a yield of 85% of theory. Th. Isolated.

Example 6

5 parts of l-aminobenzene-5-ß-hydroxyethylsulfone-2,4-disulphonic acid are heated in 80 parts of 15 parts of 15% sulfuric acid at 80 ° C. for 8 hours. The l-aminobenzene-5-β-hydroxyethylsulfone-2-sulfonic acid is obtained after neutralization of the solution with sodium hydroxide solution and evaporation to dryness in quantitative yield.

Example 7

281 parts of l-aminobenzene-4-ß-sulfatoethylsulfone are introduced into 554 parts of 100% sulfuric acid, the temperature rising to 35 ° C. Then 350 parts of 65% oleum are added dropwise and the mixture is heated at 100 ° C. for 5 hours with stirring and in the absence of atmospheric moisture until no further starting product can be detected. Then 88 parts of 50% sulfuric acid are added and the mixture is heated for a further 5 hours at 100 ° C. to cleave over-sulfated precursor. After cold stirring to 25 ° C., the mixture is stirred on ice, truncated with 950 parts of calcium carbonate, adjusted to pH = 6 with sodium carbonate and, after heating to 70 ° C., separated from the precipitated calcium sulfate hemihydrate. The l-aminobenzene-4-ß-sulfatoethylsulfone-2-sulfonic acid is used as the sodium salt in a yield of 96% of theory. Th. Isolated by evaporation. However, the desired substance can also be processed directly in the solution, for example by diazotization and coupling.

Example 8

281 parts of l-aminobenzene-4-β-sulfatoethylsulfone are introduced into 554 parts of 100% strength sulfuric acid and stirred. After adding 332 parts of chlorosulfonic acid, the mixture is heated at 140 ° C. for 3 hours with the exclusion of moisture until the starting product has completely disappeared. The mixture is then stirred until cold at 25 ° C., stirred into ice and neutralized in succession with 950 parts of calcium carbonate and 160 parts of soda. After heating to 70 ° C., the calcium sulfate hemihydrate is filtered off and the solution is evaporated to dryness. The mixture, consisting of about 10% l-aminobenzene-4-ß-sulfato-ethylsulfone-2-sulfonic acid sodium salt and about 90% 1-ami-nobenzol-4-ß-sulfatoethylsulfone-disulfonic acid-disodium salt is dissolved in 2000 parts of water, mixed with 250 parts of 100% sulfuric acid and heated to 80 ° C. for 10 hours until the oversulfated mixture fraction has been completely split back into monosulfonic acid. After neutralizing the excess acid with calcium. Soda ash is obtained by evaporation to dryness in approx. 98% purity, the l-aminobenzene-4-oxyethylsulfone-2-sulfonic acid, which by esterification at room temperature in 100% sulfuric acid into the corresponding l-aminobenzene-4-sulfato-ethylsulfone 2-sulfonic acid can be transferred.

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Claims (7)

620904 2nd PATENT CLAIMS 1. Process for the preparation of compounds of the formulas la and / or 1b wherein X is a grouping (lb) (la) io where X is a grouping -CH2-CH2-0S03H (2) -CH2-CH2-OH (3) or 15 -CH = CH, (4) means, characterized in that compounds of formula 6 20th (lb) 25th (6) S02-X -CH2-CH2-0S03H (2) -CH2-CH2-OH (3) or at temperatures between 90 and 150 ° C to compounds -CH = CH2 (4) according to formula 5 means, characterized in that compounds of formula 5 35 (5) 40 (5) treated in aqueous mineral acids with acid concentrations of 1 to 99% at temperatures of 80 to 140 ° C. 2. The method according to claim 1, characterized in that 90-96% sulfuric acid is used as the aqueous mineral acid. 3. Compounds of the formulas la and lb or mixtures thereof, prepared by the process according to claim 1. 4. Use of the compounds according to claim 3 as a diazo component for the synthesis of azo dyes. 5. Process for the preparation of compounds of the formulas la and / or lb sulfonated, then the reaction solution is mixed with water or sulfuric acid diluted with water and treated at 45 a temperature of 80 to 140 ° C. 6. Compounds of the formulas la and lb or mixtures thereof, prepared by the process according to claim 5. 7. Use of the compounds according to claim 6 as diazo component for the synthesis of azo dyes. 55